Prior art wound drains commonly comprise soft and flexible tubes, usually made of silicone, with openings in the tube wall. The openings may range in shape from small round holes to extended or even continuous slots. When the drain is placed in the wound, and the wound closed, fluids and other wound debris can flow through the openings to the interior of the tube and exit the wound through the tube. A vacuum source is often connected to the exit end of the tube to encourage drainage and maintain sterile conditions.
In anatomy, the passage within a tubular organ is called a lumen. This terminology has been adapted to describe the passageway inside the wound drain tube as well. Prior art wound drains have been made in the form of tubes with a single lumen or passageway, and also with multiple lumens to resist kinking and pinching. Multiple lumens hopefully reduce the chances that all of the drain paths will be blocked by wound debris, clots, or physical distortions of the drain. However, such solutions are less than satisfactory because for any given drain size, more lumens necessitate smaller diameter lumens. Accordingly, what is gained by redundancy is offset by a lumen size more susceptible to clogging and obstruction.